1. Field of the Invention
This invention relates to computer systems in general and, more particularly, to a pair of transceivers for receiving and deserializing serialized data at a computer monitor while transmitting serialized feedback control data obtained from a sensor back to the main computer which may be some distance away from the computer monitor.
2. Description of Related Art
The concept of sending video data to a computer monitor is generally well known. A typical video card is illustrated in FIG. 4 shown as an add-in card for an input/output (I/O) bus 340 with connector 400. Signals forwarded through connector 400 include control data (shown with open arrowheads) and data (shown with solid arrowheads). These signals may be forwarded from the I/O bus 340 into a graphics display processor 410 which manipulates the incoming video data for output to the monitor through a parallel output port 450 having parallel data lines.
Typically, 32 bit data and various control data are output from the graphics display processor 410 into video RAM (Random Access Memory) 420 such as EDO (Extended Data Out) RAM, VRAM (Video RAM) or SGRAM (Synchronous Graphics RAM), usually dual ported memory, in amounts of 1 MB (MegaByte), 2 MB, 4 MB or even 8 MB. As illustrated, 4 MB of video RAM 420 are assumed in four banks of memory as is well known in the art. Each bank outputs 32 bits of video data to a graphics interface 430 which also accepts control data from the graphics display processor 410 and outputs the video data to a RAMDAC (RAM Digital-to-Analog Convertor) 440 for conversion from digital data into the analog data required by most standard analog computer monitors. Video data may also be returned to the graphics interface 430 from the RAMDAC 440. The RAMDAC 440 outputs video data to the display of the standard monitor through the parallel output port 450. Command information for the video data from the graphics display processor 410 may also be included in the output parallel data stream to the standard monitor.
The use of a sound card to transmit audio data to a set of speakers is also well known, as is the idea that audio and video data may be combined and synchronized. Problems arise in keeping the audio and video in synch without using separate clocks that must be continually rechecked. If a single clock is used, distances between the audio card and video card may cause timing delays that must be accounted for. Is it also generally useful to have a user feedback device (e.g. mouse, keyboard, or touch screen) located on or near the display. It is typical for a separate cable to be used which connects between the computer unit itself and the feedback device.
A system is therefore needed which is inexpensive to build yet integrates audio, video and control data and its transmission from a base computer system to a monitor. A minimum number of data lines, pins and other connections are also needed. For ease of integration into legacy systems, this enhanced system should be manufacturable as a single chip solution, preferably in CMOS (Complementary metal Oxide Semiconductor) and not more expensive semiconductors such as GaAs (gallium arsenide) or BiCMOS (Bipolar CMOS). The ability to accept and transmit feedback data from the user at the monitor is also desirable. Even more desirable is the ability to keep the feedback data from the remote sensor in synch with the audio, video and control data that lead to the response of the user.